Download CIRCUITS (Ohm`s law relation V=IR)

CIRCUITS
(Ohm’s law relation V=IR)
Kristan Marshall
Meadowcreek High School
Standards:
ScSh4: Use tools and instruments for observing, measuring, and manipulation scientific
equipment
SP5: Evaluate relationships between electric and magnetic forces
b) Determine relationship among potential difference, current, and resistance
Essential Question:
How can we use circuits to determine the relationship among potential difference, current,
and resistance?
Key Questions:
What is current?
Why does charge flow?
What hinders the flow of charge?
What are the differences and similarities of series and parallel circuits?
Strategy: [90min]
• Review and introduction [5min]
• Lecture notes and graphic organizers answering the key questions [10min]
• (Class) Online applet for a complete series and parallel circuit
http://www.walter-fendt.de/ph14e/combres.htm [5min]
• (Small groups) Makes and records predictions on how current will be affected for
voltage changes across the two different types of circuits [5min]
• (Class) Voltmeter and power supply equipment demonstration and instruction on
use; activity instructions-determine if series or parallel, measure 3 voltages,
record resistances, & draw schematics [10min]
• (Small groups) lab activity-each given a completed circuit [15min]
• Lecture notes and graphic organizers explain equivalent resistances and ohm’s
law [10min]
• (Small groups) Determine currents passing through each resistor for the various
applied voltages [15min]
• (Individual) Write conclusion paragraph stating the relationship between potential,
current, and resistance. Include a comparison of your results and your predictions
[10min]
• (class) Summarize [5min]
(Extension: Use results from parallel circuits and series circuits to discuss the effect of
the type of wiring on the flow of current in a circuit.)
What do you think of when you hear “current”?
Current
Higher
gravitational
potential
Higher electrical
Potential
(voltage)
What would cause
charge to flow?
What causes the
ball to move down
the hill?
+
Lower
gravitational
potential
Lower electrical
Potential
(voltage)
Series Circuits
Parallel Circuits
1
1
2
2
3
3
4
4
5
5
Compare and Contrast
Series Circuit
Parallel Circuit
Ohm’s Law
V=I*R
Potential across battery
Total
current
X
Potential across a resistor
Total
resistance
Current
through
that resistor
X
Resistance
of that
resistor
Total
Resistance
Rseries = R1 + R2 + R3+…
R1 = 2
1/Rparallel = 1/R1 + 1/R2 + 1/R3 + …
R1 = 2
R2 = 4
R3 = 8
R3 = 8
What is the total resistance?
R2 = 4
What is the total resistance?
Group Work Rubric
Score (1-5) 5
Participation Fully
engaged
while
participating
in group’s
work
Group Work Task
Outcome
completed
as
requested;
Correct
content
Organization Very
organized
materials
and group
members
Time
Tasks
Management completed/
submitted in
the required
time frame
4
Partly
engaged
while
participating
in group’s
work
3
Not
engaged
while
participating
in group’s
work
2
Distracted
or causing
distractions;
Participating
in group’s
work
Task not
completed
as
requested;
Correct
content
Organized
materials
and group
members
Task
completed
as
requested;
Incorrect
content
Organized
materials
Task not
complete as
requested;
Incorrect
content
Tasks
completed/
submitted
within a day
of the
required
time frame
Tasks
completed/
submitted
within two
days of the
required
time frame
Somewhat
disorganized
materials
and group
members
Tasks
completed/
submitted
within three
days of the
required
time frame
1
Distracted
or causing
distractions;
Not
participating
with group
work
Incomplete
task;
Incorrect
content
Severely
disorganized
materials
and group
members
Tasks
completed/
submitted
within one
week of the
required
time frame
Individual Work Rubric
5
4
Task not
Task
Content
Individual
Effort
Organization/
Presentation
Time
Management
3
Task
completed as completed as completed as
requested;
requested;
requested;
Incorrect
Correct
Correct and
content
clear content content
Continuously Shows effort Putts forth
some effort
demonstrates on own as
well as when on own;
a full effort
major effort
assisted
when
assisted
Highly
Organized;
Somewhat
organized;
good
organized;
great
presentation average
presentation style/
presentation
style/
grammar
style/
grammar
grammar
Tasks
Tasks
Tasks
completed/
completed/
completed/
submitted in submitted
submitted
the required within a day within two
time frame
of the
days of the
required time required time
frame
frame
2
1
Task not
complete as
requested;
Incorrect
content
Putts forth
some effort
when assisted
Incomplete
task; Incorrect
content
Disorganized;
below average
presentation
style/ grammar
Very
disorganized;
poor
presentation
style/ grammar
Tasks
completed/
submitted
within three
days of the
required time
frame
Tasks
completed/
submitted
within one
week of the
required time
frame
Demonstrates
very little
effort at all